Field of the Invention
The present invention relates to a sheet post-processing apparatus, which is configured to perform a binding process for a sheet using a binding unit including a binding portion configured to drive a binding member through the sheet and bend the binding member, and to an image forming apparatus including the sheet post-processing apparatus.
Description of the Related Art
Hitherto, there is known a configuration in which a sheet post-processing apparatus is arranged in a post-stage of an image forming apparatus, which is configured to form an image using various types of image forming methods, to thereby perform a folding process or a bookbinding process. In particular, the sheet post-processing apparatus configured to perform the bookbinding process includes, for example, a stapler serving as a binding unit, and is configured to perform the bookbinding by stacking sheets conveyed from the image forming apparatus and binding the sheets for one book by the binding unit.
The binding unit such as the stapler includes a binding portion, which is configured to perform a binding operation of driving a staple serving as a binding member through a sheet by a driving force of a solenoid or a motor and bending the staple at a portion called an anvil. The staple is supplied to a cartridge of the stapler. The binding operation of the stapler may also be called a clinching operation.
When the binding process is performed on the sheet bundle by the stapler, a problem called jam, in which the staple is clogged at a portion in a stapler mechanism without being normally driven, may occur. Under such a state, the binding operation by the stapler cannot normally be performed. Also when all the staples loaded to the cartridge of the stapler are used, the binding operation by the stapler cannot normally be performed.
The stapler to be used in the sheet post-processing apparatus includes a detecting unit configured to detect that the stapler cannot normally drive the staple due to the jam or shortage of the staples. When the detecting unit detects that the stapler cannot normally drive the staple, the sheet post-processing apparatus generates an alert sound or displays an alert massage, to perform a temporarily stop.
The sheet post-processing apparatus disclosed in U.S. Pat. No. 8,141,862 controls the stapler to move to an access position for a user (or a service engineer) to perform a maintenance operation when the jam in the stapler or the shortage of the staples is detected.
The stapler subjected to the maintenance operation performs, when staples are replenished to the binding unit, a setting operation for setting the staple of the binding unit to a position (operation position), at which the staple is allowed to bind the sheet bundle, as in the sheet processing apparatus disclosed in Japanese Patent Application Laid-Open No. H11-240666. That is, the binding unit performs the setting operation in the stapler after the staples are replenished so as to reliably perform the binding process in the subsequent driving. After the maintenance operation such as the jam recovery operation (jam handling) and staple replenishment, the position of the staple is not identified inside the stapler. Therefore, the setting operation is performed as a pre-operation so that the staple is reliably driven in the clinching operation of the stapler when the binding process is performed on a subsequent sheet bundle. In the setting operation, for example, the stapler is caused to perform the clinching operation several times until the staple is fed to the operation position. This clinching operation is performed until the staple reaches the position at which the staple is driven.
In recent years, there is known a sheet post-processing apparatus additionally having a function of manual stapling in which the user inserts the sheet bundle to a position of the stapler through an opening portion formed in the sheet post-processing apparatus so that the stapler performs the binding process on the sheet bundle. In the manual stapling, the user performs positional alignment of the sheet bundle and the binding process by actuating the stapler through a button operation. Therefore, the stapler often performs the binding process at a position close to the user. In addition, the access position of the stapler, at which the user himself/herself performs the jam recovery operation or the staple replenishment, and a position of the opening portion, at which the manual stapling is performed, may be close to each other.
In such a configuration, at the time of the setting operation of the stapler, which is performed after the jam handling or the staple replenishment, when foreign matters are inserted from the opening portion of the sheet post-processing apparatus, the foreign matters may be bitten at the time of the clinching in the setting operation. The bite of the foreign matters may lead to a failure of the stapler. Further, when the sheet bundle is inserted from the opening portion at a timing when the stapler performs the setting operation, the sheet bundle may be flawed or damaged.
For example, a configuration in which the position of the opening portion for the manual stapling and the access position of the stapler are distanced from each other is conceivable. However, the configuration leads to an increase in size of the apparatus to increase costs.